How to access external JAR files from JavaScript using Rhino and Eclipse?

问题

I'm using Mozilla Rhino to write a JavaScript server application. I would like to include the HttpClient classes in my project to easily access the web, but I can't figure out how to configure my Eclipse project to get Rhino to load the HttpClient JAR file.

I have added js.jar (from Rhino) and httpclient-4.0.1.jar to my project's build path in Eclipse, and in my run configuration I have specified the Main class from Rhino's js.jar (which it finds), and in my JavaScript file I basically do this:

importPackage(org.apache.http.client.methods);
var get = new HttpGet("<some url returning json data>");
get.execute();
print(get.getResponseBodyAsString());

It fails saying this:

Exception in thread "Thread-0" org.mozilla.javascript.EcmaError: ReferenceError: "HttpGet" is not defined.

How can this be so hard? I must be doing something fundamentally wrong.

回答1:

I don't see why your code shouldn't work if your classpath is set up correctly. I would suggest to try to load the class explicitly to see if it is really available, otherwise you don't seem to have it in you classpath:

println( java.lang.Class.forName( 'org.apache.http.client.methods.HTTPGet' ) );

Rhino should be able to load to classes from external jar files without problems or extra work.

回答2:

Okay, the problem seemed to be that I had multiple references of the httpclient-4.0.1.jar file, both in my classpath and in my project's build path. Other than that, I seemed to have left out a couple of dependencies that httpclient-4.0.1.jar depend upon. After cleaning out my classpath and adding all the necessary jars to my project it now seems to find everything as expected.

Thanks for your help guys!